Artificial respirator with an auxiliary unit for temporary use



P 23, 1947- J. H. EMERSON 2,427,665

ARTIFICIAL RESPIRATOR WITH AN AUXILIARY UNIT FOR TEMPORARY USE File dJune 10, 1946 -2, Sheets-Sheet 1 Sept. 23, 1947.; EMERSON 2,427,665

ARTIFICiAL RESPIRATOR WITH AN AUXILIARY: UNIT FOR TEMPORARY USE FiledJune 10, 1946 2 sheets-sheet 2 R "Q w REA; L. N I

I lill) m I B M w WW *3 3 6% gm b v Patented Sept. 23, 1947 UNiED STATESPATENT OFFICE ARTIFICIAL RESPIRATOR WITH AN AUXIL IARY UNiT FORTEMPORARY USE 12 Claims.

This invention relates to artificial respirators for inducing breathingin persons suffering from infantile paralysis, drowning, sufiocation,etc., and more particularly to an auxiliary unit for temporary useduring periods when the patient is withdrawn from the casing of theprimary respiration unit.

This invention is an improvement upon a wellknown type of prior artartificial respirator which comprises a substantially horizontalair-tight casing having a removable end wall section to which isattached the end of a slideable bed. The removable wall section isprovided with an opening through which the patients head may be passedas he reclines on the bed. When the removable wall section is in placeagainst the end of the casing, the casing encloses the body of thepatient reclining on the bed, leaving at least his nose and mouthexposed to the atmosphere. Alternate negative and atmospheric orpositive pres sures are created within the casing in time with thenormal respiration periods of the patient. Each negative pressure periodcauses the patients chest and lungs to expand and air is automaticallydrawn into his lungs through his nose and mouth, thereby causing aninhalation. Each atmospheric or positive pressure period causes thepatients chest to collapse whereby the gases contained in his lungs areexpelled through his nose and mouth, thus causing an exhalation.

Patients sufiering from infantile paralysis remain confined in such anartificial respirator for periods ranging from a Week to many months. Inthe treatment of such patients many physi: cians find it desirable toapply hot packs to certain portions of the patients body. During suchhot-pack treatments and such prolonged treatments, access to thepatients body is required and for conveniently affording such access itis necessary to slide the bed out of the casing far enough for theattendant to apply the packs, rub or massage the patient, administerurinals, bed pans, and the like. To slide the bed out of the casing itis necessary to break the seal between the moveable end wall of thecasing and the adjacent end of the casing so that the patients chest isno longer subject to the periodic variation of pressure and artificialrespiration ceases.

In an efiort to solve this temporary lack of artificial respiration,several years ago a respirator was equipped with an auxiliary casingmounted outside of the moveable wall section, the auxiliary casing beingmoveable to a position in which it cooperated with the moveable end wallsection of the casing to form an enclosure for the patients head. Theauxiliary casing remained open while a the main respirator .casing wasin use and was closed when the patient was .slid out of the easing forsuch temporary treatments. The machine was provided with means foralternately producing positive pressure which was connected to theinterior of the auxiliary casing by a flexible hose which ran from thepositive pressure means to the floor and thence tothe auxiliary casingto provide a sufficient length for complete removal of the bed from themain casing. This arrangement functioned to force air into the patientslungs through his nose and mouth in time with normal respirationperiods.

This prior art auxiliary unit .did not meet with acceptance because thehose became entangled with the attendants feet and with the casters ofthe slideable unit and the main respirator unit; because it wasnecessary to manipulate controls to start and stop the means forproducing positive pressure; and because it was possible in the use ofthe respirator 'to close the auxiliary head enclosure when the bed wasentirely within the casing, thereby creating the possibility ofasphyxiating the patient by using the main respirator unit with the headenclosure closed with no communication between the patients nose andmouth and the atmosphere.

It is the object of this invention to provide an auxiliary respiratorunit combined with said wellknown prior art artificial respirator whichits; simple and economical in construction and which will function toprovide artificial respiration during periods when the patient isremoved from the main respirator casing.

A further object is to provide such a respirator with extensible meansfor affording communication'between the interior of the auxiliaryrespirator casing and the means for producing positive pressure whichextensible means is supported above the floor at all times and islocated out of the attendants way, thus eliminating one :of theobjections to the prior art device.

A further object is to producesuch a respirator embodying a valve, theoperation of which is controlled by the slideable unit or bed so thatcommunication between the positive pressure means and the interior ofthe head enclosure is automatically opened when the bed is slidoutwardly of the casing and such communication is automatically closedwhen the bed is returned to the casing.

A further object is to provide a single unit for creating alternatevariations in pressure within the main casing and'the auxiliary "headenclosure,

together with valves, the operation of which is controlled by theslideable unit so that communication between the pressure-varying unitand the main casing is provided when the slideable unit is closed andcommunication between the pressure-varying unit and the auxiliary headenclosure when the slideable unit is open.

A further object is to provide means associated with the main casing andwith the slideable unit which prevent closing the auxiliary headenclosure when the slideable unit is closed.

According to this invention I provide a plurality of telescoping membersto form extensible means for providing communication between the meansfor producing positive pressure and the interior of the head enclosure,one of said telescoping members being connected to the slideable bedunit and another being connected to the means for producing positivepressure, whereby when the bed is slid out of the casing the formertelescoping member moves in unison with the bed so that the extensiblemeans is automatically extended, and when the bed is slid into thecasing said telescoping member is automatically returned to its originalposition. This permits mounting this means above the floor so that itremains out of the way at all times. In a preferred embodiment theextensible means is located in the interior of the main respiratorcasing between the bottom of the bed and the bottom of the casing, butit may be mounted between the bottom of the casing and the floor or atany other locations without or within the casing. The scope of theinvention is not limited to telescoping means but is broad enough tocover any extensible means supported above the floor and extensible byoutward movement of the slideable bed unit.

According to this invention I provide a valve associated with saidextensible means and operable by said slideable bed unit whereby uponsliding the bed out of the casing communication between the positivepressure means and the interior of the head enclosure is automaticallyopened and upon returning the bed to the interior of the casing suchcommunication is automatically closed thereby eliminating the necessityfor manually operating controls when periodic positive pressure isdesired in the head enclosure.

According to this invention I provide a single unit for creatingalternate variations in pressure within the main casing and theauxiliary head enclosure, this unit being located at the end opposite tothe moveable end wall section, together with two valves, one controllingcommunication between the pressure-varying unit and. the main casing andthe other controlling communication between the pressure-varying unitand the auxiliary head enclosure. I also provide means associated withsaid valves and with the slideable unit so that communication betweenthe pressurevarying unit and the main casing is provided only when theslideaable unit is closed, and communication between thepressure-varying unit and the auxiliary head enclosure is provided onlywhen the slideable unit is open.

According to this invention I provide means on the head end of thecasing and on the auxiliary casing which prevent the closure of theauxiliary casing when the bed is completely within the main casingthereby insuring communication between the patients nose and mouth andthe atmosphere when the main casing i being utilized for artificialrespiration.

Other objects relate to the construction and mode of operation and willbe apparent from a consideration of the following description andaccompanying drawings which exemplify one embodiment of my inventionchosen for the purposes of illustration.

In the drawings Fig. 1 is a side elevation of a respirator embodying myinvention, parts being broken away and shown in section, the auxiliaryhead enclosure being illustrated in open position and the slideable unitshown in closed position; and

Fig, 2 is a vertical longitudinal section of the respirator shown inFig. 1 but with the auxiliary head enclosure shown in closed positionand the slideable unit shown in open position.

The respirator illustrated comprises the casing I0 and the removable endwall I I to which the head end of the bed I2 is attached. The casing I 0is supported by four casters I3 which roll along the floor, thesecasters being secured to a pair of legs which support the head end ofthe casing and a pair of legs 34 which support the foot end of thecasing. The removable wall section II and the bed I2 are supported bythe two casters I4 which roll along the floor, the casters being securedto a pair of legs 9|. The foot end of the bed is slideably supported onthe casing wall by means (not shown).

An opening I5 is provided in the end wall I I large enough to permit thepassage of the head of the patient therethrough. A seal is providedbetween the edge of this opening and the patients neck by a spongerubber collar I6 which is clamped against the removable end wall II byany suitable clamping means (not shown). A headrest I1 is supported bythe end wall II and is conveniently located for use by the patient whenreclining upon the bed I2. A gasket I8 is provided adjacent to the openend of the casing I0 whereby a substantially air-tight seal is formedbetween the end wall I I and the end of the casing Ill when the end wallis clamped in closed position by the clamps I9 engaging the lugs 20 (seeFig. 1).

A porthole 2| is provided in the side of the casing wall I0 permittingaccess of an attendant to the patients body when the casing is closed.

The means for producing alternate positive and negative pressureconsists of the fixed end wall 22 and the flexible leather diaphragm 23.This diaphragm is operated by an operating arm 24 which has its upperend pivotally secured at 25 to the link 26, the other end of which ispivotally secured at 21 to the rigid diaphragm extension 28. The lowerend of the operating arm 24 is pivotally secured at 29 to the connectingrod 30, and the operating arm is pivotally secured intermediate its endsat 3I to the rigid arm 32 which is secured to a cross bar 33 supportedbetween the two legs 34.

The connecting rod 30 is reciprocated back and forth horizontally by anelectric motor (not shown). Such reciprocation causes reciprocation ofthe operating arm 24 above the pivot 3|, thereby causing the diaphragm23 to be moved in and out of the cavity formed by the end wall 22. Whenthe diaphragm is moved into this. cavity (see Fig. 2) it createspositive pressure therein, and when the diaphragm is returned to theouter position (see Fig. 1) it creates negative pressure therein.

The end wall 22 is provided with three valves 35, 36, and 31. The valve35 consists of a flexible strip 38 hinged to move away from the endreceive the stem of valve 31.

wall 22 toward the interior of the casing and resiliently maintained inclosed position by a phosphor bronze spring member-39. This valve is apositive pressure safety valvewhich normally closes the opening #0 butwhich moves to open position against the pressure of the spring 39 whenexcessive positive pressure is built up by the diaphragm 23.

The valve 36 consists of a strip of leather or other flexible materialsecured to the end wall 22 at 4| and this valve serves to close theperfora-tions 42 during positive pressure periods and to opencommunication through said perforations during negative pressureperiods.

The valve 31 serves to close communication between the pressure-varyingunit and the interior of the casing II) when the bed 12 has been slidoutwardly of the casing H), as shown in Fig. 2. This valve is supportedby the cross member '45 which is secured to the end wall 22 and which isprovided with a passage adapted to slidea'bly The coil spring 43 has oneend seated upon the-cross member 45 and the other end seated upon theenlarged head portion 41 of the valve stem. When the bed is completelywithin the casing 10 the lug 48 provided on the foot end of the bedengages the enlarged head 41 of the valve stem and moves the valve 31 tothe open position shown in Fig. 1, compressing the spring 46. This openscommunication between the pressure-producing means and the interior ofthe casing. When the bed 12 is slid outwardly of the casing the spring45 moves the valve 31 to the closed position shown in Fig. 2, whereincommunication with the interior of the casing is closed. Thus when thevalve 31 is in the closed position shown in Fig. 2, positive pressurecannot be transmitted to the interior of the main casing unless thedegree of positive pressure reaches such intensity that the safety valve35 is opened. However; no substantial negative pressure can be built upby the pressureproducing means when the valve 3] is in closed position,because during the outward stroke of the diaphragm 23 the flap valve '36will be moved inwardly thereby afiording communication with atmosphericpressure which is then present within the respirator casing due to thefact that the end of the casing'is open.

The valve 50 consists of a strip of resilient metal hinged to the casingwall at 5L An adjustment member 53 is screw threaded through aninteriorly threaded perforation in the valve 50 so that the spacebetween the valve '50 and .the

casing wall may be varied by turning the knob of the member 53. Theamount of communication between the atmosphere and the interior of thecasing Ill through the perforations 52 is thus controlled by adjustmentof this knob. A pressure gauge 54' registers the degree of positive andnegative pressures which are present within the interior of the casingH). The amounts of such pressures may be controlled by means of thevalve 50 so that the valve 50 ineffect serves as a controlled leak valveby means of which the intensity of the pressures built up within themain casing are controlled.

The auxiliary head enclosure is formed by the semispherical shell 56which is pivotally secured to the moveable end wall II by means of apair of lugs 51 attached to the shell 56, a pair of arms 58 attached tothe moveable end wall -II by the cross bar 59. The pivot lugs 60 extendthrough registering perforations in the lugs 51 and the arms 58. Asubstantially air-tight seal is pro- 6 vided between the edge of theshell '56 and the face of the moveable-wall section H by the rubbergasket 6| carried by the flange on the edge of the shell 56. The shell56 is held in closed position by a pair of clamps 63 which are moveableto-locked position about its lugs 64 as in the typeof clamp commonlyused on trunks, suitcases, and the like.

A stop member 10 is secured to the wall of the casing 10 and acooperating stop member H is secured to the shell 56. These stop membersare so positioned that they engage each other when the slideable bedunit is moved inwardly of the casing with the she'll-56 in the closedposition so that they cooperate to prevent closing the end wall H of thecasing when the shell 56 is closed about the head of the patient or inthe alternative closing-of the shell 56 when the slideable bed iscompletely within the casing.

A pressure gauge 12 communicates with the interior of the auxiliary headenclosure and registers the amount of pressure therein. The valve 13 issimilar in construction to the valve -50 and may be adjusted to controlthe maximum amount of positive pressure which may be created within theauxiliary head enclosure.

Communication is provided between the interior of the head enclosure 56and the interior of at 82 and is pivotally secured to the valve stem-'83 which is slideably mounted in the axial passage of the sleeve 84which passes through and is secured to the edges of a perforation in theend wall 22. The coil spring 85 has one end seated against the end ofthe sleeve 84 and the other end seated against the enlarged head 86 ofthe valve stem 83. The vertical bar '81 is secured to the end of the bed12 and is so positioned that when the bed is slid completely into thecasing it it engages the enlarged head 86 of the valve stem 83 andslides the valve stem from left to right looking at Fig. 2, thus causingthe Valve 8| to move in a clockwise direction about the pivot 82 and toclose the end of the pipe (as shown in Fig. 1). When the bed is slideoutwardly of the casing the engagement between the bar 81 and the head86 of the valve stem is released and the spring causes the valve 8| tomove in a counterclockwise direction about the pivot 82, thus openingcommunication between the interior of the pipe 80 and the pressurechamber formed by the end wall 22 and the diaphragm 23.

In operation the motor is run continuously while a patient is on the bedl2. The motor causes the diaphragm 23 to be reciprocated in accordancewith the normal periods of inhalation and exhalation of the patient.When the end wall II is in the closed position shown in Fig. 1,alternate periods of negative and positive pressures are created withinthe casing I0. During each period of negative pressure the patientslungs are expanded, causing air to enter the lungs through the patientsnose or mouth. During each period of positive pressure the patientislungs are collapsed, causing the gases to pass out -.from the patientslungs through his nose and mouth. When the bed is slid outwardly of thecasing by releasing the clamp l9 and pulling the moveable end wall I Iaway from the end of the casing, the valve 31 is closed and the valve 8|is opened, thus opening communication between the means for creatingpressure and the auxiliary head enclosure formed by the shell 56. Theshell 56 is then moved to closed position and clamped in such positionby the clamps 63; The diaphragm then creates alternate periods ofpositive pressure within the auxiliary head enclosure, forcing fresh airinto the head enclosure during each positive pressure period.

While I have disclosed the extensible communication between thepressure-varying means and the auxiliary head enclosure as locatedwithin the casing l0, it is obvious that pipes similar to the pipes 15and 80 may be located outside of the casing ID. Furthermore a singleaccordion wall type tube may be substituted for the pipes 1-5 and 80,one end of this tube being secured to the end wall II and the other endto the end wall 22, the tube being so constructed that it extends whenthe slideable bed unit is slid outwardly of the casing and itautomatically retracts when the unit is slid inwardly of the casing, theretraction being accomplished by the accordion like pleats in the wallof the tube. A tube of such construction is thewell known type of tubeprovided between the canister and the face piece of a standard UnitedStates arm gas mask.

It is also obvious that a separate positive pressure-producing unit maybe provided and that the extensible communication may lead from suchunit to the auxiliary head enclosure and that such unit need not belocated in the end of the casing.

While I have shown and described one desirable embodiment of theinvention, it is to be understood that this disclosure is for thepurpose of illustration and that various changes in shape, proportionand arrangement of parts and substitution of equivalent elements may bemade without departing from the spirit and scope of t the invention asset forth in the appended claims.

I claim: 1. In an apparatus for producing artificial respirationcomprising a casing to receive the major portion of the body of thepatient, a bed which is slideable into and out of said casing, a casingwall section attached to and forming with said bed a slideable unit,said wall section including an opening through which the head of thepatient may be passed, means for forming a seal between said opening andthe patients neck, means to produce periodic variations in pressurewithin said casing and an auxiliary casing mounted on said slideableunit and moveable to a position in which it cooperates with saidmoveable wall section to form an enclosure for the patients head, theimprovement comprising means to periodically produce positive pressure,

extensible means providing communication between said means forproducing positive pressure and the interior of said head enclosure anda connection between said extensible means and said slideable unitwhereby the sliding of the bed outwardly of the casing automatically extends said extensible means and the sliding of the bed into the casingautomatically retracts said extensible means.

2. In an apparatus for producing artificial respiration comprising acasing to receive the major portion of the body of the patient, a bedwhich 8 is slideable into and out of said casing, a casing wall sectionattached to and forming with said bed a slideable unit, said wallsection including an opening through which the head of the patient maybe passed, means for forming a seal between said opening and thepatients neck, means to produce periodic variations in pressure withinsaid casing and an auxiliary casing mounted on said slideable unit andmoveable to a position in which it cooperates with said moveable wallsection to form an enclosure for the patients head, the improvementcomprising means to periodically produce positive pressure, extensiblemeans comprising a plurality of telescoping members providingcommunication between said means for producing positive pressure and theinterior of said head enclosure, a connection between one of saidtelescoping members and said slideable unit whereby the sliding of thebed outwardly of the casing automatically extends said extensible meansand the sliding of the bed into the casing automatically retracts saidextensible means.

3. In an apparatus for producing artificial respiration comprising acasing to receive the major portion of the body of the patient, a bedwhich is slideable into and out of said casing, a casing wall sectionattached to and forming with said bed a slideable unit, said wallsection including an opening through which the head of the patient maybe passed, means for forming a seal between said opening and thepatients neck, means to produce periodic variations in pressure withinsaid casing and an auxiliary casing mounted on said slideable unit andmoveable to a position in which it cooperates with said moveable wallsection to form an enclosure for the patients head, the improvementcomprising extensible means providing communication between means toperiodically produce positive pressure and the interior of said headenclosure, said extensible means comprising a plurality of telescopingconduits extending longitudinally of the respirator substantiallyparallel to the bed, one of said conduits being secured to saidslideable unit and communicating with the interior of said headenclosure, and another of said conduits communicating with said meansfor producing positive pressure, whereby the sliding of the bedoutwardly of the casing automatically moves said former conduitlongitudinally of the casing, a portion thereof sliding within theadjacent conduit, and the sliding of the bed into the casingautomatically retracts said former conduit to its original position.

4. In an apparatus for producing artificial respiration comprising acasing to receive the major portion of the body of th patient, a bedwhich is slideable into and out of said casing, a casing wall sectionattached to and forming with said bed a slideable unit, said wallsection including an opening through which the head of the patient maybe passed, means for forming a seal between said opening and thepatients neck, means to produce periodic variations in pressure withinsaid casing and an auxiliary casing mounted on said slideable unit andmoveable to a position in which it cooperates with said moveable wallsection to form an enclosure for the patients head, the improvementcomprising extensible means providing communication between means toperiodically produce positive pressure and the interior of said headenclosure, said extensiblemeans comprising a plurality of hollowtelescoping conduits extending longitudinally of the respirator withinthe casing and substantially parallel to i the plane of sliding movementof the bed, one of said conduits being secured to said slideable unitand communicating with the interior of said head enclosure and anotherof said conduits communicating with said means for producing positivepressure.

5. In an apparatus for producing artificial respiration comprising acasing to receive the major portion of the body ofthe patient, a bedwhich is slideable into and out of said casing, a moveable casing wallsection at one end of the casing, said wall section being attached toand forming With said bed a unitwhich is slideable longitudinally of thecasing, said wall section including an opening through which the head ofthe patient may be passed, means for forming a seal between said openingand the patients neck, a chamber in the end of the casing opposite tosaid moveable wall section, means for periodically creating positive andnegative pressures in said chamber, means providing communicationbetween said chamber and the interiorof the casing and an auxiliarycasingmounted onsaid slideable unit and moveable to a position in whichit cooperates with said moveable wall section to form an enclosure forthe patients head, the improvement comprising a plurality oftelescopingconduits extending longitudinally of the casing substantiallyparallel to the plane of sliding movement of the bed, one of saidconduits bein secured to said slideable unit and communicating with theinterior of said head enclosure and another of said conduits beingsecured to a wall of said pressure chamber and communicating with theinterior thereof.

6. In an apparatus for producing artificial respiration comprising acasing to receive the major portion of the body of the patient, a bedwhich is slideable into and out of said casing, a moveable casing wallsection at one end of the casing, said wall section being attached toand forming with said bed a unit which is slideable longitudinally ofthe casing, said wall section including an opening through whichthe-head of the patient maybe passed, means for forming a seal betweensaid opening and the patients-neck, a chamber in the end of thecasing'opposite to saidmoveable wall section, means for periodicallycreating positive and negative pressures in said chamber, meansproviding communication between said chamber and the interior of thecasing and an auxiliary casing mounted on said slideable unit andmoveable to a position in which it cooperates with said moveable wallsection toform an enclosure for the patients head, the improvementcomprising an extensible conduit, one end of said conduit being securedto said slideable unit and communicating with the interior of said headenclosure and the other end of said conduit being secured to a wall ofsaid pressure chamber and communicating with the interior thereof, avalve associated with said conduit and means associated with saidslideable unit adapted to close said valve when said slideable unit isclosed.

7. In an apparatus for producing artificial respiration comprising acasing to receive the major portion of the body of the patient, a bedwhich is slideable into and out of said casing,

a moveable casing Wall section at one end of the casing, said wallsection being attached to and forming with said bed a unit which isslideable longitudinally of the casing, said wall section including anopening through which the head of the patient may be passed, means forformingv a seal between said opening and the patients neck, a chamber inthe end of the casing opposite to said moveable wall section, means forperiodically creating positive and negative pressures in said chamber,means providing communication between said chamber and the interior ofthe casing and an auxiliary casing mounted on said slideableunit andmoveable to apositio-n in which it cooperates with said moveable wallsection to form an enclosure for the patients head, the improvementcomprising an extensible conduit, one endof said conduit being securedto said slideable unit and communicating with the interior of said headenclosure and the other end of said conduit being secured to a wallofsaid pressure chamber and communicating with the interior thereof, avalve associated with said conduit, means associated with said sildeableunit adapted to close said valve when said slideable unit is closed, avalve associated with said means providing' communication between saidpressure chamber and the interior of the casing and means associatedwith said slideable unit adapted to open said latter valve when saidslideable unit is closed.

8. In an apparatus forproducing artificial respiration comprising acasing to receive the major portion of the body of the patient, a bedwhich is slideable intoand out'of said casing, a casing wall sectionattached to and forming with said bed a slideable-unit, said'wallsection including an openingthrough which the head of the patient maybepassed; means for forming a seal between said opening and the patient'sneck, means to produce periodic variations in pressure within-saidcasing and an auxiliary casing mounted on said slideable unitandmoveable to a position in which it cooperates with said moveable wallsection to form an enclosure for the patients head, the improvementcomprising'means to periodically produce positive pressure, extensiblemeans providing communication between said means for producingpositive'pressure and the interior of said head enclosure, a connectionbetween said extensible means and said slideable unit, a valve moveableto positionsin which it opens and closes the communication-between saidmeans 'for producingpositivepressure-and said head enclosure, and meansassociated with said valve and said slideable unit whereby upon slidingof the bed outwardly of the casing said extensible means isautomaticallyextended and said valve is automatically moved to aposition wherein communication between the means for producing positivepressure-and thehead enclosure is opened and upon sliding the bed intothecasing said extensible means is automatically retracted and saidvalve-is automatically moved toa position whereinsaid communication isclosed.

9.. In an apparatus for producing artificial respiration comprising acasing to receive the major portion of the body of the patient, a bedwhich is slideable into and out of said casing, a casing wall sectionattached to and forming with said bed a slideable unit, said wallsection including an opening through which the head of the patient maybe passed, means for forming a seal between said opening and thepatients neck, means to periodically produce variations in pressure,means affording communication between said means for producing pressureand the interior of said casing and an auxiliary casing mounted on saidslideable unit and moveable to a position in which it cooperates withsaid moveable wall section to form an enclosure for the patients head,the improvement comprising means providing communication between saidmeans for producing pressure and the interior of said head enclosure, avalve moveable to positions in'which it opens and closes saidcommunication between said means for producing pressure and the interiorof the casing and means associated with said valve and said slideableunit whereby upon sliding the bed outwardly of the casing the valve isautomatically moved to a position wherein communication between theinterior of the casing and the pressure-producing means is closed, andupon sliding the bed into the casing said valve is automatically movedto a position wherein said communication is opened.

10. In an apparatus for producing artificial respiration comprising acasing to receive the major portion of the body of a patient, a bedwhich is slideable into and out of said casing, a casing wall sectionattached to and forming with said bed a slideable unit, said wallsection including an opening through which the head of the patient maybe passed, means for forming a seal between said opening and thepatients neck, means to periodically produce positive and negativepressures, means afi'ording communication between said means forproducing pressure and interior of said casing, and an auxiliary casingmounted on said slideable unit and moveable to a position in which itcooperates with said moveable wall section to form an enclosure for thepatients head, the improvement comprising extensible means providingcommunication between said means for producing pressure and the interiorof said head enclosure, a valve moveable to positions in which it opensand closes the communication between said means for producing pressureand said head enclosure, means on said slideable unit engageable withsaid valve, asecond valve moveable to positions in which it opens andcloses said communication between said means for producing pressure andinterior of the casing, and said slideable unit engageable with saidsecond valve, whereby the sliding of said bed outwardly of the casingautomatically extends said extensible means, opens said conmiunicationbetween the means for producing pressure and the head enclosure andcloses said communication between the interior of the casing and saidmeans for producing pressure, and the sliding of the bed into the casingautomatically retracts said extensible means, closes said communicationbetween said means for producing pressure and said head enclosure andopens said communication between the interior of the casing and saidmeans for producing pressure.

11. In an apparatus for producing artificial respiration comprising a,casing to receive the major portion of the body of a patient, a bedwhich is slideable into and out of said casing, a

casing wall section attached to and forming a slideable unit withsaidbed, said wall section including an openin'gthroughwhich the head of thepatient may be passed, means for forming a seal'between said opening andthe patients neck, means to periodically produce variations in pressurewithin said casing, and an auxiliary casing mounted on said slideableunit and moveable to a position in which it"cooperates with saidmoveable wall section to form an enclosure for the patients head, theimprovement comprising a stop member attached to the casing and a stopmember attached to the auxiliary casing, said stop members beingconstructed and arranged by engagement with each other to prevent theclosing of said auxiliary casing when said moveable wall section is inclosed position.

12. In an apparatus for producing artificial respiration comprising acasing to receive the major portion of the body of the patient, a bedwhich is slidable into and out of said casing, a casing wall sectionattached to and forming with said bed a slidable unit, said wall sectionincluding an opening through which the head of the patient may bepassed, means for forming a seal between said opening and the patientsneck, means to produce periodic variations in pressure within saidcasing and an auxiliary casing mounted on said slidable unit and movableto a position in which it cooperates with said movable wall section toform an enclosure for the patients head, the improvement comprisingmeans to periodically produce positive pressure, extensible meansproviding communication between said means for producing positivepressure and the interior of said head enclosure, a connection betweensaid extensible means and said slidable unit whereby the sliding of thebed outwardly of the casing automatically extends said extensible meansand the sliding of the bed into the casing automatically retracts saidextensible means and a connection between said extensible means and thestationary portion of said main respirator casing, said connections andsaid slidable unit and main respirator casing being constructed andarranged to support said extensible means at all times above the floorof the room wherein the apparatus is in use.

JOHN H. EMERSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

Article appearing in Science, Dec. 24, 1943, entitled The Return of thePulmotor as a Resuscitator: a Backstep toward the Death of Thousands, byProfessor Yandell Henderson of Yale University. (Copy in Div. 55.)

Certificate of Correction Patent No. 2,427,665. September 23, 1947.

JOHN H. EMERSON It is hereby certified that error appears in the printedspecification of the above numbered patent requiring correction asfollows: Column 6, line 6, after the word about strike out its; and thatthe said Letters Patent should be read with this correction therein thatthe same may conform to the record of the case in the Patent Ofiiee.

Signed and sealed this 11th day of November, A. D. 1947.

THOMAS F. MURPHY,

Assistant G'ommz'ssioner of Patents.

